JPS6284809A - Hot rolling mill - Google Patents

Abstract

PURPOSE:To roll a material difficult to be worked into a sheet by rolling a slab to be rolled with giving a work roll a rotating force directly from a dividing roll through a cylindrical roll covering the outside of the driving roll or indirectly through an intermediate roll. CONSTITUTION:The constitution of a rolling mill is such that a couple of driving rolls 2 and 3 are covered by cylindrical rolls 4 and 5 having a larger bore than the outside diameter of the rolls 2 and 3 and roll a slab 1 to be rolled through those rolls 4 and 5. In the case of a multi-stage rolling, work rolls 16 and 17 are driven through cylindrical rolls 14 and 15 to roll the slab 1. In the above constitution, the cylindrical rolls are driven at a high temp. because the heat conduction between the driving rolls and cylindrical rolls is restrained effectively. By the above reason, rolling for a material difficult to be worked is practicable with occurrence of cracks restrained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a hot rolling mill, and more particularly, a hot rolling mill suitable for hot working metal materials that are particularly difficult to work into thin sheets. Regarding.

(Prior art and problems to be solved) Generally, in the hot rolling method of metal materials, the material to be rolled is heated to the hot rolling temperature range and then rolled into a desired shape such as a plate by a pair of rolls (work rolls). However, since there is heat conduction from the rolled material to the work rolls, the temperature of the heated rolled material decreases.

In this respect, apart from the case of materials that require relatively low hot rolling temperatures or the case of thick plates with large heat capacity, metal materials that are difficult to process (e.g. alnico, sendust alloys) that can only be processed at high temperatures, or materials that can be processed at low temperatures In the case of a material that has a significantly high deformation resistance, the effect of such a temperature drop is large, and furthermore, it is extremely difficult to roll the material into a thin plate.

In hot rolling of such difficult-to-work materials, it is generally considered that the most effective means of preventing temperature drop is to increase the roll temperature. itself undergoes plastic deformation,
Problems arise such as: (1) the strength of the roll to withstand the rotational moment applied to it decreases; and (2) it becomes impossible to lubricate the roll bearing. Among these, materials 5, which have high strength and high hardness at high temperatures, for example, N
Although it is possible to solve the problem by selecting an i-based super superalloy, a Mo-based heat-resistant alloy, or a W-based heat-resistant alloy as the roll material, such materials are extremely expensive, so it is difficult to manufacture the entire roll using this material. Not economical.

Further, even if the bearing is manufactured without considering the economic aspect, the problem of bearing lubrication mentioned in (1) above cannot be solved.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, suppress the temperature rise of the drive roll as much as possible to prevent insufficient strength, decrease in hardness, and poor lubrication, and to reduce It is an object of the present invention to provide a hot rolling mill that prevents the temperature of a material to be rolled from decreasing by increasing the temperature, thereby making it possible to roll materials that are particularly difficult to process in the cold.

(Means for Solving the Problems) In order to achieve the above object, a hot rolling mill according to the present invention includes:
It has a drive roll, the drive roll is covered with a cylindrical roll having an inner diameter larger than the diameter of the drive roll, and if necessary, roll heating means is provided on other rolls other than the drive roll. This is a characteristic feature. In addition, in the present invention, "r hot rolling" also includes "warm rolling".

The present invention will be explained in detail below based on illustrated embodiments.

As mentioned above, in the conventional hot rolling method, it is difficult to increase the temperature of the roll surface that comes into contact with the rolled material.

Since the drive roll has an integral structure, the temperature of the entire roll increases, resulting in problems such as a decrease in roll strength and insufficient lubrication of the bearings. Therefore.

After all, there is a limit to the ability to increase the surface temperature of the roll, which must be cooled by water or oil cooling.

On the other hand, in the present invention, taking the case of the two-high rolling mill shown in FIG. Roll 4. - The material to be rolled 1 is rolled down through these cylindrical rolls 4 and 5. Of course, since this is a two-high rolling mill, the cylindrical roll 4
．． 5 acts as a work roll.

By adopting the above configuration, the contact area between the drive roll 2.3 and the cylindrical rolls 4, 5 is made as small as possible, and it becomes possible to effectively suppress heat conduction between the two, so that the drive roll It becomes possible to increase the temperature of the cylindrical roll 4.5 in contact with the material to be rolled 1 while suppressing the temperature rise of 2.3. Therefore, it is possible to avoid problems such as insufficient strength and insufficient lubrication of the bearings due to the temperature rise of the drive roll 2.3, and also to reduce the temperature of the rolled material due to heat conduction to the integral roll, resulting in stretching of the rolled material. Decreased sexuality.

It becomes possible to prevent the occurrence of cracks, etc.

In the case of the above-mentioned two-high rolling mill, the cylindrical rolls 4 and 5 serve as work rolls and roll down the rolled material 1.
In the case of a multi-high rolling mill such as a four-high rolling mill or an artificial rolling mill shown in the figure, a separate work roll is provided, and the cylindrical roll provided on the drive roll with the above configuration directly or through an intermediate roll rolls the workpiece. It is placed in contact with the roll.

That is, in the four-high rolling mill shown in FIG. 3, a pair of work rolls 16.17 are in contact with a cylindrical roll 14.15 provided around a pair of drive rolls 12.13. In the killing mill, two pairs of drive rolls 12
．． Cylindrical roll 14 provided around 12', 13°13'
．． 14', 15. A pair of work rolls 16.
17 are in contact with each other, and even more multi-high rolling mills (
(not shown) has a configuration in which an intermediate roll exists between the cylindrical roll and the work roll.

In either case, the rotational force is transmitted from the drive roll directly via the cylindrical roll or via an intermediate roll to the work roll, and the work roll rolls down the material to be rolled. Therefore, heat conduction from the rolled material is not directly transmitted from the rolled material to the cylindrical roll as in the case of the above-mentioned two-high rolling mill, but is transmitted through at least the work roll and further through the cylindrical roll. Since the temperature is transmitted to the rolls, it is possible to suppress the temperature rise of the drive rolls, and it is also easier to maintain the temperature of the work rolls in contact with the material to be rolled higher than before without worrying about the temperature rise of the drive rolls.

Furthermore, for example, in the case of a four-high rolling mill, the bending in the rolling direction is not a problem, and in the case of a six-high rolling mill, the range is not less than 174 mm, which is the geometrical outer diameter of the cylindrical roll. Therefore, the diameter of the work roll can be made smaller, which reduces the contact area between the material to be rolled and the work roll when comparing at the same rolling reduction rate, reducing the rolling load and making rolling easier. In addition to this advantage, it also has the effect of suppressing heat conduction.

In addition, in the present invention, as shown in FIG. 2, a roll heating means such as a heater (e.g., resistance heating, induction heating) 6 is arranged around the cylindrical rolls 4 and 5 to actively heat the cylindrical rolls. It is also possible to do this, so that the rolled material 1
temperature drop can be more effectively prevented. Of course, in the case of multi-high rolling mills such as four-high rolling mills and internal rolling mills, heating means such as heaters are installed on any rolls other than drive rolls such as work rolls and cylindrical rolls to actively control the temperature of the work rolls. It is possible to maintain high temperatures.

Moreover, since the present invention has the above-mentioned configuration,
Needless to say, the present invention can be applied not only to hot rolling but also to warm rolling.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to effectively suppress the temperature rise of the drive roll, thereby avoiding problems such as insufficient strength of the drive roll and poor lubrication of the bearing part. Moreover, the temperature of the parts that come into contact with the rolled material or other rolls other than the drive roll can be kept high without worrying about the temperature rise of the drive roll, and it can also be heated as necessary. Since this is possible, it is possible to effectively prevent a decrease in the temperature of the rolled material due to heat conduction to the rolls, thereby effectively preventing a decrease in stretchability and the occurrence of cracks.

It is especially suitable for rolling materials that have poor workability in cold and can only be worked in warm or hot conditions, especially materials that can only be worked at high temperatures such as sendust alloy. Suitable for rolling into thin plates.

In addition, even in the conventional hot rolling of general metal materials, the material to be rolled becomes colder as the plate thickness decreases, and deformation resistance increases as the temperature decreases, so it is difficult to reach a thickness that can be reduced by hot rolling alone. had its limits. This is because when the present invention is applied to general metal materials, the temperature drop of the rolled material can be suppressed.

Even with hot rolling alone, it is possible to obtain thinner products than with conventional methods. Therefore, there is an effect that the processing cost of the next step of cold rolling can be reduced, and the present invention is also suitable when applied for such purpose.

[Brief explanation of drawings]

1 and 2 are side sectional views showing roll arrangement, etc. of a two-high rolling mill according to one embodiment of the present invention, and FIG. 3 is a side sectional view of a four-high rolling mill according to another embodiment. FIG. 4 is a side sectional view of an internal rolling mill according to still another embodiment. 1... Rolled material, 2.3.12.12', 13.1
3'... Drive roll, 4.5, 14.14', 15
．． 15'...Cylindrical roll, 6...Heater. 16.17... Work roll. Patent applicant: Showa Denko K.K. Patent attorney Hisashi Nakamura Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A hot rolling mill characterized in that it has a drive roll, and the drive roll is covered with a cylindrical roll having an inner diameter larger than the diameter of the drive roll. 2. In the case of a two-high rolling mill, the hot rolling mill according to claim 1, wherein the material to be rolled is rolled down through the cylindrical rolls. 3. In the case of a multi-high rolling mill, the hot rolling mill according to claim 1, wherein a pair of work rolls is rotated via the cylindrical roll to roll down the material to be rolled. 4. It has a drive roll, the drive roll is covered with a cylindrical roll having an inner diameter larger than the diameter of the drive roll, and roll heating means is provided on other rolls other than the drive roll. hot rolling mill.